Composition and process
A solvent extraction composition is comprised of one or more orthohydroxyarylaldoximes and one or more othohydroxyarylketoximes, and one or more equilibrium modifiers in an amount providing a degree of modification of the orthohydroxyarylaldoximes from about 0.2 to 0.61
1. A solvent extraction composition comprising one or more orthohydroxyarylaldoximes and one or more orthohydroxyarylketoximes, and one or more equilibrium modifiers selected from the group consisting of 2,2,4-trimethyl-1,3-pentanediol mono-isobutyrate, 2,2,4-trimethyl-1,3-pentanediol mono-benzoate, 2,2,4-trimethyl-1,3-pentanediol di-isobutyrate, 2,2,4-trimethyl-1,3-pentanediol di-benzoate, isobutyl heptyl ketone, nonanone, 2,6,8-trimethyl-4-nonanone, diundecyl ketone, 5,8-diethyldodecane-6,7-dione, and tridecanol, in an amount providing a degree of modification of the orthohydroxyarylaldoximes present from about 0.2 to 0.61.
2. A solvent extraction composition according to claim 1 wherein the degree of modification is from about 0.4 to 0.6.
3. A solvent extraction composition according to claim 1 or 2 wherein the orthohydroxyarylketoximes are compounds of formula:
wherein
R 1 is an optionally substituted hydrocarbyl group
R 2 is an optionally substituted ortho-hydroxyaryl group, and salts thereof, and the orthohydroxyarylaldoxime are compounds of the formula:
wherein
R 3 is an optionally substituted ortho-hydroxyaryl group, and salts thereof.
4. A solvent extraction composition according to claim 3 wherein the orthohydroxyarylketoxime is a 5-(C 8 to C 14 alkyl)-2-hydroxyacetophenone oxime, and the orthohydroxyarylaldoxime is a 5-(C 8 to C t4 alkyl)-2-hydroxybenzaldoxime.
5. A solvent extraction composition according to claim 1 wherein the orthohydroxyarylketoxime is 2-hydroxy-5-nonylbenzophenone oxime, and the orthohydroxyarylaldoxime is 2-hydroxy-5-nonylsalicylaldoxime and the equilibrium modifier is 2,2,4-trimethyl-1,3-pentanediol di-isobutyrate.
6. A process for the extraction of a metal from solution in which an acidic solution containing a dissolved metal is contacted with a solvent extraction composition, whereby at least a fraction of the metal is extracted into the organic solution, characterised in that the solvent extraction composition comprises a water immiscible organic solvent, one or more orthohydroxyarylaldoximes and one or more orthohydroxyarylketoximes, and one or more equilibrium modifiers selected from the group consisting of 2,2,4-trimethyl-1,3-pentanediol mono-isobutyrate, 2,2,4-trimethyl-1,3-pentanediol mono-benzoate, 2,2,4-trimethyl-1,3-pentanediol di-isobutyrate, 2,2,4-trimethyl-1,3-pentanediol di-benzoate, isobutyl heptyl ketone, nonanone, 2,6,8-trimethyl-4-nonanone, diundecyl ketone, 5,8-diethyldodecane-6,7-dione, and tridecanol in an amount providing a degree of modification of the orthohydroxyarylaldoximes present from about 0.2 to 0.61.
7. A process according to claim 6 wherein the metal is copper, cobalt, nickel, manganese or zinc.
8. A process according to claim 7 wherein the degree of modification is from about 0.4 to 0.6.
9. A process according to any one of claims 6 , 7 or 8 wherein the orthohydroxyarylketoximes are compounds of formula:
wherein
R 1 is an optionally substituted hydrocarbyl group
R 2 is an optionally substituted ortho-hydroxyaryl group, and salts thereof,
and the orthohydroxyarylaldoxime are compounds of the formula:
wherein
R 3 is an optionally substituted ortho-hydroxyaryl group, and salts thereof.
10. A process according to claim 9 wherein the orthohydroxyarylketoxime is a 5-(C 8 to C 14 alkyl)-2-hydroxyacetophenone oxime, and the orthohydroxyarylaldoxime is a 5-(C 8 to C 14 alkyl)-2-hydroxybenzaldoxime.
11. A process according to claim 10 wherein the orthohydroxyarylketoxime is 2-hydroxy-5-nonylbenzophenone oxime, and the orthohydroxyarylaldoxime is 2-hydroxy-5-nonylsalicylaldoxime and the equilibrium modifier is 2,2,4-trimethyl-1,3-pentanediol di-isobutyrate.